<?php namespace Zmsun\Http\Header;class Age implements IHeader{protected$deltaSeconds=null;public static function fromString($headerLine){$header=new static();list($name,$value)=GenericHeader::splitHeaderLine($headerLine);if(strtolower($name)!=='age'){throw new \InvalidArgumentException('Invalid header line for Age string: "'.$name.'"');}$header->deltaSeconds=(int)$value;return$header;}public function getFieldName(){return'Age';}public function getFieldValue(){return$this->getDeltaSeconds();}public function setDeltaSeconds($delta){$this->deltaSeconds=(int)$delta;return$this;}public function getDeltaSeconds(){return$this->deltaSeconds;}public function toString(){return'Age: '.(($this->deltaSeconds>=PHP_INT_MAX)?'2147483648':$this->deltaSeconds);}}